An interpersonal relationship is a strong, deep, or close association or acquaintance between two or more people that may range in duration from brief to enduring. This association may be based on inference, love, solidarity, support, regular business interactions, or some other type of social connection or commitment. Interpersonal relationships thrive through equitable and reciprocal compromise, they are formed in the context of social, cultural and other influences. The context can vary from family or kinship relations, friendship, marriage, relations with associates, work, clubs, neighborhoods, and places of worship. They may be regulated by law, custom, or mutual agreement, and are the basis of social groups and society as a whole. Early adolescent relationships are characterized by companionship, reciprocity, and sexual experiences. As emerging adults mature, they begin to develop attachment and caring qualities in their relationships, including love, bonding, security, and support for partners. Earlier relationships also tend to be shorter and exhibit greater involvement with social networks. Later relationships are often marked by shrinking social networks, as the couple dedicates more time to each other than to associates. Later relationships also tend to exhibit higher levels of commitment. Most psychologists and relationship counselors predict a decline of intimacy and passion over time, replaced by a greater emphasis on companionate love (differing from adolescent companionate love in the caring, committed, and partner-focused qualities). However, couple studies have found no decline in intimacy nor in the importance of sex, intimacy, and passionate love to those in longer or later-life relationships. Older people tend to be more satisfied in their relationships, but face greater barriers to entering new relationships than do younger or middle-aged people. Older women in particular face social, demographic, and personal barriers; men aged 65 and older are nearly twice as likely as women to be married, and widowers are nearly three times as likely to be dating 18 months following their partner's loss compared to widows.
According to Maslow's hierarchy of needs, humans need to feel love (sexual/nonsexual) and acceptance from social groups (family, peer groups). In fact, the need to belong is so innately ingrained that it may be strong enough to overcome physiological and safety needs, such as children's attachment to abusive parents or staying in abusive romantic relationships. Such examples illustrate the extent to which the psychobiological drive to belong is entrenched.
Power is the ability to influence the behavior of other people. When two parties have or assert unequal levels of power, one is termed "dominant" and the other "submissive". Expressions of dominance can communicate intention to assert or maintain dominance in a relationship. Being submissive can be beneficial because it saves time, emotional stress, and may avoid hostile actions such as withholding of resources, cessation of cooperation, termination of the relationship, maintaining a grudge, or even physical violence. Submission occurs in different degrees; for example, some employees may follow orders without question, whereas others might express disagreement but concede when pressed.